Final answer:
The claim that particles move closer together when heated is false; as particles in a material gain kinetic energy from heat, they tend to move apart due to increased energy, leading to expansion.
Step-by-step explanation:
The statement that when a material is heated, its particles move closer together is false. When materials are heated, the particles typically move faster due to the increase in kinetic energy resulting from the thermal energy that has been absorbed. Because of this increased motion, particles tend to move apart, not closer together. This effect can be observed in the expansion of materials when they are heated and is essential for understanding phenomena such as thermal expansion.
As a material is heated without a change in state, such as melting or vaporizing, the increase in thermal energy causes an increase in temperature, associated with a higher average kinetic energy of the particles. Consequently, the intermolecular forces are overcome by the increased movement, causing solids to expand and gases to occupy more volume. This is contrary to the cooling of a substance, where a decrease in kinetic energy allows the intermolecular forces to dominate, pulling particles closer together, leading to contraction or a phase change from gas to liquid or solid, depending on the conditions.
In summary, heating leads to increased distance between particles in most typical materials, which is why the original statement is incorrect.